title: An integrated exact mass spectrometric strategy for comprehensive and rapid characterization of phenolic compounds in licorice.
abstract: BACKGROUND
  Licorice (Gancao) is derived from the dried roots and rhizomes of Glycyrrhiza species (Leguminosae) and appears as a component herb in about 60% of traditional Chinese medicine (TCM) prescriptions. Modern pharmacological studies have shown that flavonoids are one class of the major components responsible for the bioactivities of licorice. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/QTOF MS) has proven to be a powerful tool for rapid profiling and identification of natural products in complex herbal medicines.
  
  
  METHODS
  A UPLC/QTOF MS method was established for the first time for profiling and structural characterization of the phenolic compounds (most of them flavonoids) in licorice. The combined use of data-independent acquisition (MS(E) ) and data-dependent acquisition (DDA) was illustrated.
  
  
  RESULTS
  Fifteen flavonoid reference compounds were used to explore the fragmentation pathways. Compound identification was based upon the exact mass, general fragmentation behaviors, retention times, UV absorption, and the related botanical biogenesis. As a result, a total of 51 compounds were characterized, three of which were reported for the first time.
  
  
  CONCLUSIONS
  The LC/MS analysis for each injection took less than 9 min. The developed method is fast, accurate and reliable due to its high resolution and high efficiency characteristics as a result of combining both UPLC separation and QTOF exact mass measurement.
authors.affiliation: National Engineering Laboratory for TCM Standardization Technology, Shanghai Research Center for Modernization of Traditional Chinese Medicine, Shanghai Institute of Materia Medica, Haike Road 501, Shanghai, 201203, P.R. China.
authors.forename: Tongtong
authors.initials: T
authors.lastname: Xu
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Li
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.forename: Qiurong
authors.initials: Q
authors.lastname: Wang
authors.forename: Wangping
authors.initials: W
authors.lastname: Deng
authors.forename: Xiayan
authors.initials: X
authors.lastname: Pang
authors.forename: Kate
authors.initials: K
authors.lastname: Yu
authors.forename: Baohong
authors.initials: B
authors.lastname: Jiang
authors.forename: Shuhong
authors.initials: S
authors.lastname: Guan
authors.forename: De-an
authors.initials: DA
authors.lastname: Guo
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000191:economics / Q000379:methods; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D005419:Flavonoids / Q000032:analysis*; D006035:Glycyrrhiza / Q000737:chemistry*; D013058:Mass Spectrometry / Q000191:economics / Q000379:methods*; D010636:Phenols / Q000032:analysis*
chemical_list: D004365:Drugs, Chinese Herbal; D005419:Flavonoids; D010636:Phenols